JPH0629523B2 - Turbine housing - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a turbine housing, and more particularly to a turbine housing formed of ceramic and configured to be joined at a fitting portion of a center housing.

[Prior Art] As a conventional turbine housing of this type, for example, there is one disclosed in Japanese Utility Model Laid-Open No. 57-171104 as shown in FIGS. 2A and 2B. Here, 1 is a turbine housing made of ceramic, and 2 is a metal center housing in which a rotor shaft 3A of the turbine rotor 3 is axially supported via a bearing (not shown).

The ceramic turbine housing 1 is provided with a cylindrical portion 1A, a scroll portion 1B and a shroud portion 1C which are inserted into the fitting portion 2A of the center housing 2, and a metal casing 4 for holding the housing 1 and a ceramic turbine. A buffer material 5 having a high heat insulating property is filled between the housing 1 and the housing 1.

Thus, a turbine housing composite body composed of the casing 4, the cushioning material 5 and the ceramic housing 1
Insert the 10 into the fitting part 2A of the metallic center housing 2,
The abutment surface of the housing composite 10, that is, the abutment portion 4A of the casing 4 is brought into contact with the corresponding fixed portion 2B of the center housing 2 so that the turbine housing composite 10 is supported by the center housing 2. Composed.

However, in such a conventional turbine housing, since the turbine rotor 3 has been made ceramic in recent years, the portion in contact with the working gas, which tends to have a higher temperature, is made ceramic. In addition, the weight of the rotor is 1/3 that of a metal rotor, so the energy when a rotor breaks is small, so it is thin and lightweight, but its cylindrical part 1A and scroll part 1B and shroud portion 1C are all integrally formed of thin ceramics, and there is a problem in molding due to the complicated shape, resulting in high cost.

[Purpose] An object of the present invention is to provide a ceramic-based turbine housing having a composite structure using an inexpensive material that is easy to manufacture, focusing on such conventional problems.

[Configuration of the Invention] In order to achieve the above object, the present invention is formed in a cylindrical shape having a rotor shaft as a shaft center, which is fitted into a fitting portion of a center housing that supports a rotor shaft of a turbine rotor. And a ceramic shroud portion formed in a tubular shape with the rotor shaft as an axis along the blade end portion of the rotor, the tubular portion of the center housing It is formed integrally with the flange part that abuts the fixed part,
The shroud portion is integrally formed with a flange portion provided at an end of the shroud portion on the gas discharge side, and the tubular portion and the shroud portion are integrated by a scroll portion made of a heat-resistant heat insulating material to form a turbine housing inner shell. A member is formed, a heat insulating layer of foamable ceramic is provided outside the turbine housing inner jacket member, and an outer jacket member made of hard strength material is provided outside the heat insulating layer.

Thus, according to the present invention, the portion fitted to the fitting portion of the center housing and the shroud portion along the rotor blade end portion are formed into a cylindrical shape with ceramics together with their respective flange portions, and these are made heat-resistant. Integral with the scroll part made of heat insulating material to make the turbine housing inner member,
Further, a heat insulating layer made of foamable ceramic and a jacket member made of hard strength material are provided on the outer side thereof. With such a structure, the heat insulating property of the turbine housing is improved, and the tubular portion and the shroud portion serve as a rotor shaft. Since it has a simple shape as a cylindrical rotating body with an axis,
When it is made of ceramic, it can be molded very easily and the moldability is improved.

Further, since the flange portion abutting against the fixed portion of the center housing and the flange portion provided at the gas discharge side end of the shroud portion are integrally formed with the tubular portion and the shroud portion by ceramic, respectively, the center housing and the gas discharge side are formed. The heat transfer from the high-temperature gas to the other members contacting the ends is reduced, and the heat resistance is improved, so that the bond strength is improved.

Embodiments Embodiments of the present invention will be described in detail and specifically below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention. In this example, only the cylindrical portion 11A inserted into the fitting portion 2A of the center housing 2 and the shroud portion 11C formed along the blade end portion of the ceramic turbine rotor 3 are made of ceramic. In this case, the flange portion 11D to be brought into contact with the center housing fixing portion 2B of the tubular portion 11A and the flange portion 11E provided at the gas discharge side end portion of the shroud portion 11C are integrally formed with the tubular portion 11A and the shroud portion 11C, respectively. Molded.

That is, since each of the above-mentioned parts 11A, 11C, 11D and 11E has a shape as a cylindrical rotating body having the rotor shaft 3A as a center line, it can be formed extremely easily as compared with the conventional case.

Next, the tubular portion 11A and the shroud portion 11C formed in this way
And the rotor inlet portion 12 is formed between the scroll portion 11B and the scroll portion 11B with ceramic fibers (S
A turbine housing inner jacket member (11) is formed by being formed of a heat insulating material such as cast iron (iO ₂ ) and cast and integrated with each of the parts (11A to 11E).

The scroll portion 11B formed of the heat insulating material does not need to be sintered at a high temperature and may be dried normally in a low temperature atmosphere. Next, the inner surface of the scroll portion 11B is coated with a heat-resistant curing agent (ceramic such as zirconia-based or alumina-based) 13 by spraying or painting.
To prevent the surface of the heat insulating material from peeling off due to the gas flow rate of up to 300 m / s.

Reference numeral 14 denotes a second heat insulating layer formed along the outer surface of the inner member 11. In the present example, the second heat insulating layer 14 is formed of a foamable ceramic material (for example, shirasu mixed with a foaming agent at a predetermined temperature). It is obtained by foaming when left in the atmosphere of, or is formed of foam cerabon [... trade name (manufactured by Shikoku Kaken Co.)]. By thus forming the scroll portion 11B with a layer made of a heat insulating material such as ceramic fiber and further laminating the second heat insulating layer 14, a remarkable adiabatic hardening can be brought about by these double layers.

By the way, the thermal conductivity of general insulation is about 0.1-0.3 Kcal / m.
In contrast to h ° C, in the case of foam ceramic materials, it is about 0.04 to 0.07 Kcal / mh ° C. For example, when the thickness of the above-mentioned two-layer heat insulating material is 15 mm, the gas temperature is 1000 ° C. On the other hand, the wall temperature outside the heat insulating wall is maintained at about 260 to 300 ° C.

In this embodiment, however, the outer jacket member 15 for maintaining strength is formed by covering the housing inner jacket member 11 on which the second heat insulating layer 14 is formed as described above. For example, aluminum or engineering plastic is suitable for the mantle member 15, and the mantle member 15 is used for the member 11 and the layer 14 described above.
In order to be integrated with, for example, the second heat insulating layer 14 is formed on the inner member 11.
The outer jacket member (15) is formed by surrounding the mounted object as a core.

In the example of FIG. 1, in order to integrate the turbine housing with a composite structure, the outer jacket member 15 is first molded of aluminum or engineering plastic, and the housing inner jacket member 11 is used as a core. It is needless to say that a foamable ceramic material may be poured into the space between and to foam to form the second heat insulating layer.

[Effects] As described above, according to the present invention, the turbine rotor is formed into a cylindrical shape that is fitted in the fitting portion of the center housing that pivotally supports the rotor shaft, and that has the rotor shaft as its axis. A ceramic cylindrical portion and a ceramic shroud portion formed along the blade end portion of the rotor, the ceramic shroud portion having the rotor shaft as an axis, and the cylindrical portion is fixed to the center housing. Is formed integrally with a flange portion that comes into contact with the shroud portion, the shroud portion is integrally formed with a flange portion provided at the gas discharge side end portion of the shroud portion, and the tubular portion and the shroud portion are heat-resistant heat insulating materials. The turbine housing inner member is integrally formed by a scroll portion made of, and a heat insulating layer of foamable ceramic is provided on the outer side of the turbine housing inner member, and a hard strength material is formed on the outer side of the heat insulating layer. By providing the outer cover member, the tubular portion and the shroud portion have a simple shape as a tubular rotating body having the rotor shaft as the axis, and therefore, it is possible to form the ceramic material very easily and formability is improved. Further, it is easy to form a turbine housing inner jacket member that is integrated with the scroll portion by using the heat insulating material, and further, at the gas discharge side end portion of the flange portion and the shroud portion that abut the fixed portion of the center housing. Since the flange portion provided is integrally formed with the cylindrical portion and the shroud portion by ceramics, heat transfer from the high temperature gas to the center housing and other members contacting the gas discharge side end portion is reduced,
Since the heat resistance is improved, the bond strength is good.

Thus, the manufacturing cost of the turbine housing that houses the turbine rotor can be reduced, and the heat insulation can be greatly improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of the structure of the turbine housing of the present invention, FIG. 2A is a sectional view showing an example of the structure of a conventional ceramic turbine housing, and FIG. 2B is a sectional view taken along the line AA of FIG. 2A. . 1 ... Turbine housing, 1A, 11A ... Cylindrical part, 1B, 11B ... Scroll part, 1C, 11C ... Shroud part, 11D, 11E ... Flange part, 2 ... Center housing, 2A ... Mating Part, 2B ... fixed part, 3 ... turbine rotor, 3A ... rotor shaft, 4 ... casing, 4A ... contact part, 5 ... cushioning material, 10 ... turbine housing complex, 11 ... inside Coat member, 12 ... Rotor inlet part, 13 ... Coating, 14 ... Second heat insulating layer, 15 ... Outer member.

Claims (2)

[Claims] 1. A ceramic cylindrical portion that is fitted into a fitting portion of a center housing that rotatably supports a rotor shaft of a turbine rotor and is formed into a cylindrical shape with the rotor shaft as an axis. A ceramic shroud formed in a tubular shape having the rotor shaft as an axis center along an end portion, and the tubular portion is integrally formed with a flange portion that abuts a fixed portion of the center housing. The shroud portion is integrally formed with a flange portion provided at the gas discharge side end of the shroud portion, and the tubular portion and the shroud portion are integrated by a scroll portion made of a heat-resistant heat insulating material in a turbine housing. A shell member is formed, a heat insulating layer of foamable ceramic is provided outside the turbine housing inner shell member, and an outer shell member made of a hard strength material is provided outside the heat insulating layer. Over bottle housing. 2. A turbine housing according to claim 1, wherein the gas passage forming surface of the turbine housing inner member is hardened.